Electrochemical sensors that use two electrodes (e.g. a reference electrode and a sense electrode) attached to an electrolyte to determine the concentration of a particular species of gas are known. An electrochemical sensor can be made sensitive to a particular species gas by forming the electrodes using different material and/or different processes. Such electrochemical sensors can be used to discern the species concentration in a mixture of gases by exposing both electrodes to the mixture. Relevant examples of such electrochemical sensors are described in commonly owned U.S. Pat. Nos. 7,074,319; 7,722,749; 7,828,955; and 7,975,537, all issued to Wang et al. However, it has been observed that if the concentration of a certain reference gas in the mixture suddenly changes (i.e. a change in the reference concentration), there may be a transient error in the sensor signal output by the electrochemical sensor that could be misinterpreted as a change in the species concentration.